A 63-year-old Cromwell man has been charged with careless use of a motor vehicle causing death after a crash on the outskirts of Alexandra in July that killed a 23-year-old American woman.

Central Otago sub-area commander senior sergeant Ian Kerrisk said "the charges have been brought after a thorough investigation of the crash and the circumstances surrounding it. We have a clear picture of what occurred and it is a matter that is now best dealt with through the court process."

Maxwell James Birtles faces two charges – careless use of a motor vehicle causing death, and careless use of a motor vehicle causing injury – relating to the crash at Butchers Dam.

Kirra Lee Smith, who had been living in Wanaka, died instantly after her vehicle and a four-wheel-drive driven by Birtles, collided head-on about 12.50pm on July 29.

Birtles' and the passenger from the car Ms Smith was driving, 22-year-old British woman Tessa Senior, both suffered moderate injuries.

"Police are grateful for the assistance given by all the parties involved, their families and other witnesses," Mr Kerrisk said.

''This is a situation which is tragic for all involved. I am very grateful for the manner in which everyone has conducted themselves; especially given this has been a very emotional time for them all."

Birtles is expected to appear in the Alexandra District Court on October 16.